After WWI, the Middle East was aportioned to the West. The Ottoman Empire sided with the Germans, and when the Turks lost, France got Lebanon and Syria, and England got what is now Israel, Jordan, and the West Bank.

In In 1923, the British divided Palestine into two administrative districts. Jews would be west of the Jordan river. The land east of the Jordan was aportioned to the Arabs of the area. This became the Arab Palestinian Nation of Trans-Jordan in 1946. For the Palestinian Arabs, this was to be their Arab Palestinian homeland (out from under British rule). The remaining 25% of Palestine west of the Jordan River was to be the Jewish Palestinian homeland. Many of these Jews had either been there throughout the history of that area, or had come in the late 1800's to the early 1900's. They too had a vested interest in becoming a nation...no less so than the Arabs of the area.